Applications of Solar Heat for Industrial Processes (SHIP) frequently require the coupling of the solar energy source with a thermal energy storage (TES) system, in order to accommodate the solar irradiance dynamics and its fluctuations with the eventually variable heat demand of the process. The complexity of the physical mechanisms that take place during the phase change process is still a challenge to an accurate modelling while keeping the calculation time low enough to provide fast calculations. This communication presents a simplified 1D model of a real latent thermal energy storage system with extended surfaces. The model has been validated against a 3D CFD model, providing good results and low calculation times. Preliminary results for a future real application are presented to show the applicability of the model.